Originally Posted by Mellow Mushroom
closed phones resonate in the midrange, but it's minor, and they still manage to sound better than open phones
Actually, many closed headphones suffer from severe resonance issues. This is due primarily to their excessive empty air space inside the ear cups (and regardless of how thick the ear cup material is, the material still resonates, but in a different way) with insufficient or no damping material inside, and their closed backs give the sound nowhere to go but back through the transducers. Some of the EXPENSIVE closed headphones are just as underdamped as their cheaper cousins.
As far as the transducers used in closed headphones are concerned, had a headphone manufacturer designed a closed headphone to sound good in a properly damped closed headphone shell, they must use a transducer which would otherwise sound a bit too dark in an open-air headphone configuration; otherwise, the sound would become thin and bright. And such designing costs money. Undamped (or underdamped) closed headphones at every single price point are the norm given the desire to cut costs at the manufacturing level - and this underdamping allows the manufacturer to share the same transducers between open and closed headphones at the same price point. The end result is that in most cases, closed headphones simply don't sound quite as good as open headphones at competitive price points. On the other hand, vintage closed headphones don't sound very good, if only due to their poor design with expensive parts. And I do admit that closed headphones can equal or beat open headphones in sound quality - if done right.
In the end, I blame the cost-cutting at the headphone manufacturers, and not the inherent limitations of the closed headphone design, for the underperformance of closed headphones versus competitively priced open headphones.